1. Field of the Invention
The present invention relates to improvements in umbrella frames, and more particularly, to umbrella frames of the type which can be collapsed to form a relatively small package when not in use.
2. Description of the Prior Art
This type of umbrella is known from U.S. Pat. No. 3,902,514, issued Sept. 2, 1975,H. Weber, inventor, which discloses an umbrella frame comprising a stick, a crown at the upper end of the stick and a plurality of dome ribs distributed about the crown, each extending in a direction away from the crown. Each of the dome ribs has three sections, with the outermost section pivotable about a pivot point at the outer end of the middle section, and the middle section being telescopic on the inner section hinged to the crown. A main runner slides on the stick, and each dome rib is supported by a support structure, and each support structure includes a stretcher member pivoted to the main runner at one end and to the middle dome rib section at the other end thereof. A strut member is hinged to an auxiliary runner sliding on the stick between the main runner and the crown, and at the other end thereof is hinged to the stretcher member intermediate the hinge points of the stretcher member. A control link is pivoted at one end to a stretcher member at a point spaced from the pivot point of the stretcher member to the dome rib, and the other end of the first link member is hinged to an inward extension of the outer dome rib section forming a quadrilateral with the middle section of the dome ribs and the portion of the stretcher member between the pivot points of the control link member and the dome ribs, and the dome ribs as well as the portion of the extension of the outer dome rib section so as to control the folding of the outer dome rib section from a position folder onto the middle dome rib section to a position extended away from the middle dome rib section and linearly aligned therewith.
The umbrella, in accordance with this patent, automatically folds closed as the runner on the stick is moved towards the handle with the outer dome rib sections immediately folding onto the middle dome rib sections which may then be telescoped within the inner sections. The movement is positive and allows the dome ribs to be collapsed to one-third of its normal length. However, when the cover fabric is wet, there is no way to partially collapse the umbrella so as to allow the umbrella material to dry without folding it and thereby causing the wet cover material to be bunched together and thus delay the drying.